1. Field of the Invention
This invention relates to organosilicone terpolymers per se, to their employment as finishing agents for natural and synthetic textiles, and to textile materials embodying them.
2. Description of the Prior Art
The application of finishing agents to textiles has been practiced for many years. Textile fabrics treated with durable press resin require treatment with softening agents to achieve commercially acceptable hand, strength, and wrinkle recovery.
A number of silicone compounds have been employed as softening agents in the prior art. Usually, these are silicone fluids which are applied in the form of emulsions. They impart a soft feel to the fabric, improve processibility, and are generally more efficient to use than the available organic softening agents.
In some instances, the silicone fluids contain reactive groups which cause them to crosslink on the fabric, resulting in a highly durable finish.
One such reactive silicone softening agent is an epoxy-modified polydimethyl-siloxane which is described in U.S. Pat. No. 3,511,699. Other softening agents are two-component systems comprised of silanol endblocked silicone oil emulsions and alkoxysilanes such as methyl trimethoxysilane crosslinker. The two components are premixed immediately prior to their application to the fabric.
The above mentioned reactive silicone fluids which are employed as softening agents and which impart durable softness, are hydrophobic in nature. Hydrophobicity is undesirable in many textile applications because it contributes to fabric soiling and it is believed to inhibit washing effectiveness. Moreover, the hydrophobicity of these softening agents inhibits the absorption of body moisture in clothing fabrics, and thus can cause the wearer to experience a damp sensation.
U.S. Pat. No. 3,565,845 describes siloxane-polyoxyalkylene block copolymers which are capable of forming durable finish on fibrous materials treated therewith. Silicone glycol nonionic type copolymers which are hydrophilic, such as those described in U.S. Pat. No. 3,992,332, can be blended with anionic phosphate esters and employed as a softening agent in fabric laundering. But these hydrophilic softeners are non-crosslinking. Consequently, the softness which they impart is not highly durable and the softener must be applied in subsequent launderings.
The textile art is seeking an effective softening treatment which is at once highly permanent, hydrophilic, and economical to use.